24 
PALEONTOLOGY OF NEW-YORK. 
d Tly^L (to*, 
413. 3. RP§©iHYCWS PUDICUS (n.sp.). 
Pl. VIII. Fig. 6 a, b. 
General form elliptical, transversely rugose or nearly smooth ; a deep longitudinal groove 
along the centre reaching nearly to each extremity. 
This species is evidently closely allied to the preceding ones in its generic characters, though 
it presents no elongated stem. The smaller and younger specimen is nearly smooth, while the 
larger is distinctly rugose. There appears to be a regular gradation from P. clavatus , through 
the present species, into the succeeding one, which is very strongly characterized. 
Position and locality. Blackstone’s quarries. 
414. 4. RUSOPHYCUS BILOBATUS. 
Pl. IX. Fig. 1 a, b, c. 
Fucoides bilobal^a. Vanuxem, Geol. Report, 1842, pag. 79, fig. 1. 
Distinctly bilobate, with the lobes often separating at one extremity ; form broadly oval or 
subquadrangular, very rugose transversely, with a deep longitudinal groove running the entire 
length. 
This species is readily recognized by its distinctly bilobate form, appearing as if composed of 
two separate bodies joined along a central line. It is always strongly and irregularly wrinkled 
transversely; the two extremities being depressed, while the centre is elevated. In several 
specimens, there arises from between the two lobes a round slender stem, which extends to the 
length of several inches. It is impossible to say whether this stem is supported by the portion 
described, which is the root; or whether the stem originally supported the larger bilobate 
portion as a floating appendage. In most cases very little evidence of the existence of this stem 
is preserved ; while in Others, it appears to have been an actual portion of the plant. 
This species is always found on the under side of the strata, attached on one side only ; so 
that the side presented in the view is the lower side in its position in the stratum. They are 
extremely abundant in some thin layers, but appear to have existed, like most of the other 
species, only during a limited interval, and never to have extended through any considerable 
thickness of the strata. The preceding species, which are allied to this one, are found in a lower 
position, and never associated in the same strata with it. 
Fig. 1 a. A well marked specimen with a stipe attached. 
Fig. 1 i. A flattened specimen, showing the point where a stem was broken off 
Fig. 1 c. A large and well preserved specimen, showing no marks for the attachment of a stem. 
Position and locality. Gaylord and Norton’s quarry near New-Hartford, Oneida county, 
about one hundred feet above Blackstone’s quarries, which is the position of the two preceding 
species. ( state Collection.) 
